Twenty-one years after King Edward I’s accession, there arose a naval war between France and England. In 1286, Edward was the first who appointed a person to the office of Admiral of the English Seas, as we find William de Leybourne styled “Admiral de le Mer du dit Roy d’Angleterre,” at an ordinance made at Bruges concerning the conduct of the ships of England and Flanders in that year; and about the same time first mention is made of an admiral of France, named Florent de varenne, whose successor, Enguerrand, was “Admiral de la Flotte du Roi Philippe le Hardi,” yet never was the sea more infested by piracy than in 1293, the period referred to. The feeble execution of the laws had given licence to all kinds of men; and a general appetite for rapine, followed by revenge for it, seemed to infect the mariners and fighting merchant-traders of the time, and tempted them on the smallest provocation to seek redress by immediate and merciless retaliation on the aggressors.
It chanced that a Norman and an English vessel met near the coast of Bayonne (De Mezeray has it Guienne), and both having occasion for water, sent their boats ashore at the same time, and, as misfortune would have it, to the same spring, upon which there immediately ensued a quarrel for precedence. In the squabble a Norman drew his dagger and attempted to stab an English seaman, who grappling with him, hurled him to the ground. The Norman was said to have fallen on his own dagger; be that as it may, the man was slain, and from this petty scuffle between two obscure seamen about a cask of water, there grew a bloody war between two great nations, involving half of Europe in the quarrel. The mariners of the Norman ship laid their complaints before the King of France, who, without caring to inquire into the matter, bade them “take revenge, and trouble him no more about it.” Though more legal than usual in applying to the crown, they required but this hint to proceed to immediate outrage.
Meeting an English ship in the Channel, they boarded her, and hanging some of the crew, together with some dogs, from the yard-arms, in presence of their shipmates, bade them inform their countrymen that “vengeance was now taken for the blood of the Norman killed at Bayonne.”
This injury, accompanied by circumstances so insulting, was speedily resented by all the mariners of the Cinque Ports, who, without the empty formality of appealing to King Edward, retaliated by committing precisely the same barbarities on all French vessels without distinction; and the French in return preyed upon the ships of Edward’s subjects, Gascon as well as English: and soon armed piratical craft of all kinds swarmed in the Channel and Bay of Biscay in pursuit of each other, the sovereigns of both countries remaining perfectly indifferent the while. The English formed private associations with the Irish and Dutch seamen, the French with the Genoese and Flemings; and the animosities of these lawless spirits became more and more violent.
A fleet of 260 Norman vessels set sail to the south for wine, and in their passage seized all the English ships they met, and hanging or drowning the crews, made spoil of the cargoes, and arrived in triumph at St. Mahé, a port in Bretagne. Filled with fresh fury by this incident, the English ports fitted out a fleet of eighty sail, stronger and better manned, to take revenge. Depredations had now been carried to such a length, that at last the nations agreed on a certain day to decide the dispute with their whole naval strength, and a large empty ship was placed in the Channel midway between the coasts of England and France to mark the spot of the engagement.
On the 14th April, 1293, they met in close battle. Long and obstinate was the engagement, and no quarter was either asked for or given; in the end the French were totally routed, and the -greater part of their ships taken, sunk, or destroyed, and “the majority of their crews perished in the ocean.” It has been alleged that the loss of the French was 15,000 men. If so, it can only be accounted for by the circumstance that the returning Norman fleet was transporting a considerable body of troops from the south.
Matters were now looking serious; and French King Philip IV, enraged by a defeat so murderous and disgraceful, dispatched an envoy to London demanding reparation. He did more, for he cited Edward to appear in his Court of Parliament, as his liege man and vassal, being Duke of Guienne, and having done homage on his knees as such before Philip, at Paris, in 1274. The English king sent his brother; but Philip, dissatisfied with this equivocation, declared him contumacious, and seized his French possessions. On finding himself in something like the same absurd feudal snare he had prepared for the Scots, Edward was exasperated; the more so when he found France making preparations to invade England at a time when his hands were full with his northern neighbours: so, to anticipate any descents on the coast, besides three formidable fleets which were to protect it, he equipped a fourth consisting of above 330 ships, with a body of 7,000 men-at-arms and archers on board, under the command of the Earl of Lancaster, to recover his forfeited duchy of Guienne. He sailed to the mouth of the Garonne, took a town or two, and thence went to Bourdeaux and Bayonne, after the capture of which he died; but all this did not prevent a French fleet of 300 sail, under the command of Matthew de Montmorenci and John de Harcourt, assisted by Thomas de Tuberville, an English traitor, from landing at Dover, and reducing that town to ashes, ere the men of the country rose, and compelled the invaders fly to their ships with considerable loss.
The Royal Navy, a History from the Earliest Times to the Present/Volume 1/Chapter 8 by W. Laird Clowes
In 1294, large English fleets were assembled in the Narrow Seas, one in the North Sea, being under Sir John de Botetort, one in the Channel, being under Sir William de Leybourne, and one, in the Irish Sea, being under a knight named Ormond.  On June 26th, the barons of England were ordered to be at Portsmouth by September 1st, to accompany the king to Gascony; and in July Edward himself was at Portsmouth. Meanwhile, wood was hewn for the equipment of above two hundred ships to carry horses; the keepers of all the ports were directed to suffer no man, ship, boat or vessel to quit the kingdom; and John Baliol, King of Scots, who had done homage to Edward in 1292, was enjoined not to allow any ships or men to leave his country for abroad.
The army destined for Gascony consisted of twenty thousand foot soldiers, with five hundred men-at-arms. It sailed from Portmouth on August 1st, but, off the Cornish coast, was dispersed by bad weather and driven into Plymouth, whence it did not sail again until the beginning of October. Entering the Gironde, the fleet appeared about the 28th of the month in the Dordogne before Castilion, which place surrendered at once. Thence the expedition proceeded up the Garonne to St. Macaire, which submitted on the 31st. On the following day the ships anchored off Bourg. On November 8th they were off Blaye, whence they sailed to Bordeaux, where they remained for two days. Failing to reduce it, they again mounted the Garonne to Lieux, where the horses were landed after having been seventeen weeks and some days embarked.
The main expedition was followed by the Earls of Lancaster and Lincoln with reinforcements, probably conveyed in vessels which the Cinque Ports had been ordered to send to Portsmouth by September 8th; but this division did not sail until the spring of 1295. In the interval, in October, 1294, certain goods belonging to
French subjects were directed to be seized and sold and the proceeds paid into the Exchequer.
Sir Henry de Turberville has been mentioned as having played a gallant part in the defeat of the French at the Battle of the South Foreland in 1217. A relative of his took less honourable share in the naval history of the reign of Edward I. This knight, Sir Thomas de Turberville, had been made prisoner by Philip IV.; and, eager to advance himself, no matter at what cost, turned traitor. He suggested in 1295 that Philip should fit out a large fleet and crowd the vessels with troops; and that, in the meantime, he himself should go to England, report that he had made his escape, and endeavour to obtain from his sovereign a command at sea, or the custody of the ports, or both. He would then, on seeing the approach of the French, deliver up his trust, the agreed signal that his plot had been successful being his own banner hoisted above that of the king. Philip accepted the offer, promised Turberville large rewards, and kept two of the traitor’s sons as hostages.
Turberville reached England, but, though kindly received, failed to obtain the wished-for command. Philip, on his part, collected more than three hundred ships from Marseilles, Genoa and other places, and sent them to cruise off the English coasts, in waiting for the expected signal. Not seeing it the commanders grew impatient, and dispatched five of their best galleys to reconnoitre more closely. One of these landed at Hythe. To induce the intruders to advance inland, the king’s forces retired before them, and then, suddenly turning, fell upon them and killed them all to the number of two hundred and forty, afterwards taking and burning the galley. The other four galleys rejoined their main body, which was far too formidable to be attacked by such ships as were at the disposal of the English commanders on the spot. Turberville’s treachery was still unsuspected in England; but the assemblage of Philip’s large fleet could not but be known; and, with a view to resisting invasion, letters were dispatched on August 28th and 30th to the Bishop of London and other prelates and priors instructing them to take the necessary measures in case the enemy landed; and on September 28th the sheriffs were informed that danger was apprehended from the machinations of certain foreign ecclesiastics residing near the sea-board, and recommending their immediate removal inland.
But, before this, a descent had actually been made. On August 1st the French fleet had appeared off Dover, and had suddenly landed about fifteen thousand men, who had seized the town and burnt great part of it. The people had fled, but recovering their courage, and being reinforced, had attacked the invaders so vigorously as to kill five thousand of them and to put the rest to flight. Some had escaped to the ships, others had taken refuge in the fields, where they had been afterwards found and massacred. Thirty seamen had maintained themselves in the cloisters of the abbey until night, when they had got away in two boats, only. however, to be followed in the morning by two large craft and sunk. In the whole affray but fourteen Englishmen had lost their lives.
The repulse at Dover and the non-appearance of Turberville’s signal disheartened the French, who returned to their ports and dispersed; yet Turberville’s treason was still undiscovered and might have gone unpunished but for the suspicions of a clerk, who delivered to Edward a letter which led to the conspiracy being laid bare, and to the culprit’s execution.
The retirement of the French opened the Channel to the operations of English cruisers. The ships of the Cinque Ports captured fifteen Spanish vessels full of merchandise, bound for Damme, and brought them into Sandwich; and some Yarmouth ships landed a force at Cherbourg, fired the town, robbed an abbey, and carried off an old priest.